This invention relates to a multipurpose structure for use as a stand-alone utility platform that can be supported and levelled above the ground, or as a load-carrying platform on a wheeled vehicle such as trailer or pickup truck. Said structure is convertible between different modes of usage, including: an extended platform, an open-ended U-shaped assembly with flatbed and sidewalls, an open-top utility container, or a compactly collapsed structure with a cargo carrying rack.
Although the article of the present invention can be used as a stand-alone structure removably attachable to a wheeled vehicle to be carried by the latter, for descriptive purposes in the following disclosure we mainly refer to said structure as forming an integral part of a trailer.
Many previous patents teach the art of the collapsible trailer""s construction, which allows the trailers to be reduced to a more compact non-used shape for stowage or for expanding the trailer body in order to carry a larger or longer load on the flatbed area. When used on the highway, these trailers are still too bulky and as a result they obstruct the driver""s rear view, they do not offer fuel economy or the safest possible towing performance (e.g., FR 1.081.030; U.S. Pat. No. 2,557,347; U.S. Pat. No. 3,715,141).
Most of the structures from prior arts are confined to one specific purpose where, in the majority of cases, they would be used as a camper (e.g. U.S. Pat. No. 5,988,731; U.S. Pat. No. 4,198,996). Such single use structures failed to attract the majority of consumers who find it hard to justify the price and storage space required for owning such device. The above comment is also applicable to each of the many interchangeable transportation apparatuses that one can attached to a wheeled chassis as disclosed in U.S. Pat. No. 3,524,659.
Many prior arts (e.g. U.S. Pat. No. 5,080,426)offer an expandable design where a large top or cover section of the trailer is folded out and then supported on the ground independent of the main body. Such designs require a flat campground surface for proper erection, demanding more skill from users. A challenging campground would have uneven surfaces, unleveled surfaces or surfaces interspersed with small rocks and/or bushes. In any of these cases, it would be impossible to set up campers as taught by the above prior arts or to erect conventional tents on the ground without first preparing the surface.
Very often tents are custom fitted to the trailers and are erected up with an unfolding or raising up of different parts of the trailer (e.g., U.S. Pat. No. 5,375,902). The prior art does not teach a type of trailer construction that can be used with any standard tent design; this would conveniently complement the need of tent owners.
Many patents (FR 1.081.030; UK 2 035 915; U.S. Pat. No. 3,715,141) disclose a platform construction whereby side sections are partially supported from the ground and require additional adjustment from that of the center portion during each set up. The concepts presented in U.S. Pat. No. 2,557,347 use stakes and receiving pockets and that of FR 1.315.737 use a larger trailer chassis than the usable flatbed surface as a means to support the folded-out sidewalls. Such assemblies do not provide a solid stand-alone platform, they have limited load-carrying capacity on the extended sidewalls or cannot be deployed quickly from one configuration to the other.
There is no prior art that teaches the construction of a convertible trailer having side sections that can be quickly raised from a horizontal position and be held rigidly in an upright position relative to the flatbed area to form an open ended U-shaped utility trailer. Such configuration is very useful for the transportation of long articles such as lumbers, canoe, etc.
It is, therefore, a principal object of the present invention to provide a multipurpose trailer which can be easily and quickly converted between different modes of usage: a working or camping platform, a U-shaped trailer with flatbed and rigid sidewalls, an open-top utility box trailer, or a compact cargo-rack trailer. The versatility of the current invention will justify the cost and space requirements involved in owning such a trailer.
It is another object of the present invention to provide a maintenance-free camper that offers instead, an extended camping platform that can be utilized with any standard tent design. This is intended to make tent usage more functional and practical, to offer a low cost alternative to owning a camper, and to provide a complementary product for tent owners.
It is still another object of the present invention to provide a compact trailer for highway use. Having the most compact body cross-sectional area, this trailer offers a minimal frontal draft for highest fuel efficiency, does not obstruct the driver""s field of vision through rear view mirrors and is the least affected by lateral wind. This insures the easiest and safest highway towing performance. The other modes of usage present a larger trailer body but are only required for hauling bulkier loads at relatively slower speeds.
It is a further object of the present invention to reduce the cost of such a multipurpose trailer by minimizing the number of components. This is achieved through a judicious design of the many components of the trailer, having them perform different tasks during different modes of usage.
Furthermore, it is another object of the present invention to provide a cargo-rack on a wheeled vehicle installed at a much lower deck elevation compared to racks normally equipped on a car roof. This tremendously facilitates the loading and unloading of cargo items.
Many other objects will in part be obvious and in part be described hereinafter.
The main structure of the present invention comprises a center portion, which offers a main flatbed area, and side sections that are configurable into different positions. Said center portion is firmly erected on the ground by means of four adjustable post assemblies which extend downward at the four corners of said flatbed area. Said posts firmly engage the ground""s surface to support and level said center portion in a stationary and levelled plane above the ground.
Side sections are pivotally connected on opposite sides of said center portion by multiple hinges having pivot axes parallel to the longitudinal edge of said center portion. These hinges located near the upper edges allow the side sections to be unfolded to a position where their surfaces lie in a coplanar relationship with the top surface of said center portion. In this position the bottom edges of the side sections are supported by a plurality of vertical load bearing surfaces disposed on the connected sides of the center portion. Side sections are therefore fully cantilevered from the center portion, forming extensions on both sides of the main flatbed area.
This type of extended platform is very easy and quick to set up on any ground condition, side sections do not need to be supported from the ground, thus no additional adjustment is required. The platform can be used for working or camping. For example, when used as a platform for the erection of a camping tent, it offers many benefits that include the following:
A platform that can accommodate any stand-alone standard tent design, offering a flat surface for the sleeping comfort of tent users independent of the campground condition.
Preventing the ingress of water, insects, or reptiles into the tent living area.
Isolating of the tent floor from ground""s surface humidity and dampness.
Eliminating the need for preparation of the campground surface under the tent platform.
Fastening means are provided for removably erecting any standard tent design on the platform. These allow a quick erection and removal of a tent without disturbance to the trailer for the other modes of usage. As a result, provision can also be made for erecting many different tents on the same trailer platform, thus allowing the greatest flexibility to users.
When the trailer is used for carrying a load, center posts on the adjustable post assemblies are retracted upwardly away from the ground. In this movement the upper end portions of said posts are caused to engage with holding rings located at forward and rear ends and near freely swinging side of the hingedly connected side section. This provides a releasable holding means to hold said side sections in a generally upright position forming an open-ended U-shaped trailer with flatbed and sidewalls for the transportation of elongated articles such as lumber, ladder, canoes, etc.
In another utility mode, end sections are slidably attached at opposite ends of the trailer to form an open-top utility box trailer for the containment and transportation of comminuted materials such as sand, garden soil, etc. A cover may be added to fully enclose the utility box trailer.
During highway use, the side sections are compactly folded and securely held down on top of said center portion to offer the lowest possible trailer profile. A cargo rack is provided on top surfaces of the folded panels for the transportation of general cargo, such as luggage for a highway trip. An enclosure is also included on the rack for the secure holding and locking of loose or small articles such as hand tools or camping accessories.
The cargo-carrying feature of the rack can also be used in other folded positions of the side sections. For example, it is a place where garden tools are securable while the trailer is used for transporting gardening materials.
Moreover, the racks are designed to stiffen the side sections and provide strength and load handling capacity, allowing side sections to be used as cantilevered platform extensions, this will be explained later in the description of the preferred embodiment of the invention. The resulting high bending stiffness of the side sections also allows for them to be supported only at the front and back ends. This spares the middle section from any disturbances, and maximizes the usable flat platform surface area.
The preferred embodiment is that of the body structure of a trailer, however as aforementioned, the present invention can be used as a stand-alone unit and can be removably attached to and be carried by a wheeled vehicle such as a trailer or pickup truck. Once on site it can be set up, firmly anchored, supported and levelled on the ground. The wheeled vehicle can then be detached for other uses.
In another alternative the structure can also form an integral part of the body of another type of wheeled vehicle such as a pickup truck. This is where it would replace the cargo tub on the chassis of said vehicle.